1. GIS in Water Resources Term Project
Utah State University
GIS in Water Resources Term Project
Identifying spatial and temporal extent of critical condition for water wells in Salt lake valley
Ali Forghani
Nov 2011

2. Introduction: Water Resources: - Surface water - Groundwater
In this project:
Groundwater conditions in Salt lake valley (HUC8= ) have been studied
- Considering groundwater elevation

3. Objectives:
1- Obtaining interpolated surface of groundwater elevation in the study area
2- Specifying the critical areas
3- Specifying the regions possibly affected by artificial recharge system
4-Obtaining interpolated surface of depth of unsaturated zone
5- specifying the regions with high pumpage cost

4. Note: 1- lacking a complete data for extraction wells
2- lacking the monthly data for observation wells esp. after year 2000

5. Needed data: 1- Digital Elevation model (DEM)
2- groundwater elevation data
- USGS:“water level below land surface” (Depth of groundwater)

6. -Not existing stations in northwest of the region
-defining 4 new stations near surface waters (depth=0)

7. Objective 1: interpolated groundwater elevation
2 procedures: 1- determining groundwater elevation in each observation well and then interpolating 2- interpolating depth of water table and then subtracting it from DEM
The results of procedure 2 was more reliable.

9. Objective 2: Specifying the critical areas
Critical area: the area with decrease in water table more than critical value
Obtaining the map of groundwater elevation differences in desired time periods
Definitions:
Yearly critical value:1m
10 years period critical value:4m

10. Critical area: (10 years period)
(Critical value:4m)
Red regions (3.8%)

11. Critical area: (1 year period)
(Critical value:1m)
Red regions (14%)

12. Objective 3:
The regions with highest increase (possibly affected by artificial recharge)
Dark green region

13. Objective 4: interpolated surface of unsaturated depth

14. Objective 5: Regions with high pumpage cost (in which depth of unsaturated zone is high)
Definition:
high depth: depth more than 30m

15. Suggestion for further studies
Obtaining the complete data for extraction wells in the region
Using different interpolation methods and comparing results

16. Thanks for your attention
Any Questions???